Herba Inutilis: The Evolution of Weed Extirpation
An intriguing examination of the historical roots of modern-day control of the scourge of every gardener — weeds.
Once there was a world without weeds. Then, there were … weeds. This is a review of the arc of development of weed control from the earliest time period when there was no such thing as a weed, to primitive attempts to deal with these competitors to humans’ early attempts at agriculture and then through the rigorous examination of how best to deal with weed problems in Britain and Ireland which ultimately found its way to America.
Present day weed control typically is presented under the framework of “Integrated Weed Management” and there are very well-respected Weed Science programs at major universities throughout the world. While farmers and gardeners as recently as two or three generations ago struggled to find information on weed control techniques, much has been written on the subject in the past several decades and exhaustive resources are now available on the internet and through cooperative extension programs in many states.¹
Integrated Weed Management typically is expressed as involving four methods of weed control: Cultural, Mechanical, Biological and Chemical.
Cultural control employs horticultural methods and practices to control weeds. For example, growing rows of lettuce close to each other serves to deprive the soil underneath of sunlight which inhibits the growth of weeds.
Mechanical control is the most direct way to rid land of weeds as it basically involves physically removing them by hand or tool. However, care needs to be taken not to revert to historical inefficiencies as exemplified by this Youtube video which takes 2 minutes and 14 seconds to demonstrate how to remove a single weed by hand:
As will be discussed in more detail below, mechanical control of weeds was the predominant method throughout much of history, leading to use of human labor at the sacrifice of higher utilizations and purposes, for example, children laboring in fields instead of attending school.
Biologic weed control is the one method which has not changed much over the years as it essentially involves using animals to control weeds.
Chemical weed control greatly expanded in the 20th century and this article winds up at the dawn of that modern development about 100 years ago. However, primitive forms of herbicides were used centuries ago, foreshadowing the need and utility of weed control methods which were effective in terms of cost, time and labor.
So, let’s start at the beginning. When humans were in our stage of development of being hunters and gatherers, that is, pre-agricultural, there was no such thing as a weed. In other words, a “weed” is a human construct in that what grew out of the ground was really of no concern as certain unwanted plants were not competing with desired plants under cultivation, since cultivation was not yet occurring at the time.
A review of literature reveals that the concept of a weed, or unwanted plant, came about, at least according to biblical writings, when Adam was promised thorns and thistles…
and Jonah became tangled in water weeds on his way to his experience with the whale.²
Further found in preserved ancient biblical literature was the Parable of the Tares:
‘The kingdom of heaven is like a man who sowed good seed in his field; but while men slept, his enemy came and sowed tares among the wheat and went his way. But when the grain had sprouted and produced a crop, then the tares also appeared.
“‘So the servants of the owner came and said to him, “Sir, did you not sow good seed in your field? How then does it have tares?” He said to them, “An enemy has done this.” The servants said to him, “Do you want us then to go and gather them up?”
“‘But he said, “No, lest while you gather up the tares you also uproot the wheat with them. Let both grow together until the harvest, and at the time of harvest I will say to the reapers, ‘First gather together the tares and bind them in bundles to burn them but gather the wheat into my barn’”’” (Matthew 13:24–30).
Indeed, it is very difficult to distinguish between the tares weed and a shaft of wheat:
However, it is generally thought that the first stabilized agriculture came about near the Euphrates and Tigris rivers in Mesopotamia and the Nile River in Egypt about 6,500 B.C.
Along the way in the B.C. years, here is an example of a hand sickle which came into use, although probably just for harvesting purposes:
By 1000 B.C. there is evidence of more agricultural tools being developed such as this drag harrow formed from a tree limb with short stubs of branches for tilling, then an A-shaped log with wooden pegs to form teeth and even later adding a collar so that an animal could pull the device — but still no mention in the ancient B.C. literature about such tools being used to remove weeds.
By the first century A.D. Roman writers were beginning to mention the deleterious effect of weeds on planted crops and describing various metal-bladed tools for agricultural purposes, such as the these:
Burning of crop stubble also was taking place, in part to destroy leftover weeds.
Olive oil, tree pitch and grease also were noted in the first century A.D. as harmful to seeds, but not yet referencing use to destroy weeds. One early agent of an herbicidal nature was mentioned in the first century A.D. namely, “amurca,” the liquid residue after oil was drained from crushed olives. A first century writer noted that amurca was poisonous to weeds as well as to ants and moles. Where amurca flowed from the oil presses onto the fields the ground became barren so that, “ … it is usually poured around the roots of trees, chiefly olive trees, and wherever noxious weeds grow in the fields.”³ Whether it was an agent from the olive juice itself, or perhaps as a result of salt added to the process is not entirely clear, but by all accounts the use of amurca is an example of one of the first herbicides.
One biologic method of weed control, however, had evolved in Asia, with grass carp controlling unwanted vegetation in rice paddies.
But, generally, for most of post-agricultural history weeds were a burden and a curse to be endured and about which not much could be done except by laborious hand methods. Available literature from the first 1,000 years or so A.D. suggest that other agents were used to kill unwanted plants including salt, a mixture of salt and duck excrement, mixtures of herbs and salt and even preparations involving human feces. While salt was leaned on as an herbicide, it generally was unsatisfactory as it dissolved and ran off when wet and was thus a threat to desired plantings, but along the way people came to only drop it only on the crowns of thistles, use over gravel paths, apply to fallow land in the Fall and mix certain amounts with seed. Nevertheless, physical labor remained the primary methods of removing weeds.
One of the first regulations concerning weeds to be found was a law in Scotland from 1212–1249 which had severe penalties to tenants who seeded weeds on land or who did not destroy certain weeds. Enforcement was reportedly so effective that the region became known for grains free from weed seeds and sheriff’s enforcers were noted not to be able to find enough weeds to collect their fines.
Eventually, as literature and the arts began to expand, references to weeds began to appear more frequently.
“Who weeding slacketh, good husbandry lacketh.”
Poetic agricultural writer Thomas Tusser, 1557
Shakespeare even used weeds as a pejorative prop in his plays:
… I will go root away
The noisome weeds, which without profit suck
The soil’s fertility from wholesome flowers.
- Richard II, Act III, Scene 4
Also, who can forget King Lear and his crown of weeds?
One agriculturist rose to prominence in the 1700’s in England and who ended up having a great influence on many horticultural issues of the day, including weed control. This man:
… who turned out to be the inspiration for this English rock band’s name:
The 4th edition of Jethro Tull’s “An Essay on the Principles of Vegetation and Tillage,” as well as other writings, reflect him putting a bullseye on the back of weeds and making them public enemy №1.⁴ This excerpt is an example of his emphatic message in this regard:
Mr. Tull’s ideas and creations have been said by some to have been a basis of the British Agricultural Revolution. His most well-known invention was the grain drill, which for the first time planted grain crops in straight rows, whereas previously seeds were scattered by hand over plowed fields. This later would cause great problems while attempting to weed the fields as the weeders had a difficult time making sure they were weeding the weeds and the not the crop (which also reflected that not much had changed in weed management from the time of the Parable of the Tares). Having all of the crop seed in rows meant any plant life outside of the rows was a weed. It also allowed Tull’s cultivation tool consisting of a horse-drawn harrow to be used between crop rows to loosen the soil between the drilled rows and to physically kill weeds. He also developed a horse-drawn hoe which dug out roots and grasses from the ground which were tossed to the side to dry and die.
Here is an image of a drawing of his ground-breaking grain seed drill invention:
Illustrators of plants also began to recognize individual weed plants, even in 1771 portraying them as objects of beauty.⁵
1806 saw one of the first writings which discussed specifically the subjects of weeds in the garden, not just out in the fields on a farm.⁶
This publication used the word “extirpation” by way of describing what farmers and gardeners desired to do to weeds, with extirpation defined as “to destroy completely” or “pull up by the root.” This signals an increased use of direct and aggressive language used by those describing methods of weed control. As will be seen, terms such as “destroy,” “kill” and “bleed to death” are used. The phrase “Integrated Weed Management” or other such euphemisms are nowhere to be found in the horticultural literature of the 18th or 19th centuries. It can be imagined that Jethro Tull and his cohorts may very well have reacted to such as a term by imploring the user not to be so indirect and to stop beating around the bush so to speak, but, rather, to clearly express the necessary actions to be taken against such a pernicious interloper. Perhaps “extirpation” was the Integrated Weed Management of its day, although it expresses such a deadly goal in such an elegant way that perhaps its use should be resuscitated, maybe with academic degrees in Weed Extirpation being awarded instead of Weed Science — after all the whole purpose of weed science, integrated weed management and the like is to kill, destroy, indeed to extirpate, weeds.
In the above report, Mr. William Pitt of Wolverhampton, England succinctly sets forth the prevailing view of weeds:
He goes on to compile a list of 22 different types of weeds which he describes as “… the principal intruders into the garden.” He then counsels gardeners to pull up weeds before they seed and states that, at least in Staffordshire, the principal tools used in the garden for “destroying” weeds are the spade, the three-fanged fork and various hoes.
Ways to extirpate weeds and how to communicate and educate on the subject became a more frequent topic during the British Agricultural Revolution as reflected by this publication:
Within this Essay on the Weeds of Agriculture, a letter from a farmer is summarized as follows:
So, it is known at least by the early 1800’s there still did not exist a preeminent text which advised farmers and gardeners on methods of killing weeds. Mechanical, cultural and biologic methods still ruled the day, with advanced herbicides about a century away, although as will be seen crude attempts at using chemical herbicides were under way.
Nonetheless, a general mood of not being able to control the presence of weeds prevailed, leading some countries and local governments to pass very rigorous weed control laws. Ireland, for example, in 1860 passed a national law which allowed a landowner to give notice to any adjoining property owner to cut down and destroy weeds on the property. Some present-day local HOA regulations have nothing over the Irish as the adjoining landowner then had 14 days to extirpate the weeds or be subject to a stiff financial penalty; or the local Justice also could issue an order allowing the property owner to go onto the land and remove the weeds himself. Here is the printed cover page of the law.⁷
The war on weeds in Ireland, and elsewhere, was eloquently declared and set forth in an extensive report in the 1875 “Agricultural Statistics, Ireland” which contained a detailed “Appendix Containing Information Regarding the Extirpation of Weeds.”⁸ The report first noted the “lamentable” prevalence of weeds in Ireland and that “several Grand Juries have given directions to the County Surveyors to take all necessary steps to prevent the great injury to the farming classes which has hitherto arisen from the growth of weeds along the sides of public roads.”
So, what means did Ireland then employ to attack this lamentable problem?
That’s right, children. The Commissioners of National Education were told to instruct the country’s teachers to direct the attention of the school children to the importance of destroying weeds when found growing on their parents’ farms. Religious school leaders as well as heads of workhouses also were brought into this effort to deploy children across the Emerald Isle in an effort to extirpate weeds. An example was given of a farmer who paid local children to collect weeds and add them to a heap of weeds and other plant refuse which would burn continuously for weeks at a time, with the ashes then later used as a soil amendment. The particular essay describing this process concluded by noting, “Always destroy the life and reproductive power of weeds, even by fire, if necessary.”
This fascinating and eloquent appendix did not stop there, however. It then continued to enlist the writings of this, as he was described, “most observant and popular author(s)”:
Yes, even Charles Dickens had something to say about eradicating weeds, and he did not mince his words in literally declaring war on weeds in a periodical of the time:
The Appendix concludes in a very articulate and impassioned manner by noting that “as far as weeds are concerned, Ireland is the wealthiest country in the world” and the “evil is almost universal.”
Nonetheless, artists continued to illustrate in very detailed and appealing ways plants known as weeds.⁹
By the late 1800’s the aggressive approach to weeds seen in Europe made its way to the United States. One letter to the Editor of Science magazine in 1892 from someone at an “Experiment Station” in North Carolina suggested several definitions he had found for weeds.
He added that his own definition of what constitutes a weed is, “Any plant which from its situation or inherent properties is hurtful to human interests; a vegetable malefactor.”¹⁰
Then in 1892 a bulletin from a West Virginia Agricultural Experiment Station reflected the still predominant use of mechanical means of addressing weeds in the United States, while discussing the nascent use of forms of herbicides. The bulletin referenced a poll taken of growers and reported the use of salt but concluded that it must be used in great quantity and was useful only in very limited areas. Lime was meeting with only limited success. The use of coal, oil or kerosene was not recommended as it was too costly and only effective when poured generously upon small areas of soil. While sulphuric acid was noted to kill any weed, it had to be applied directly to each individual rootstock, thus rendering the process a tedious and costly one. The bulletin concluded, “Experience and experiment have conclusively proven that any extended use of chemicals as weed killers is always attended by more expense and labor than the results can possibly compensate for.”¹¹
An 1897 report from the United States Department of Agriculture listed America’s “Twenty-Five Most Harmful Weeds” and how to control and eradicate them. Among the suggestions are frequent hoeing or spudding, continued cultivation, use of coal oil or carbolic acid, thick seeding with smothering crops, mowing before flowers open, burning mature plants, salting the plants and pasturing sheep on them, hot brine, kerosene, hand pulling, use of clean seed, application of lime to acidic soils to stimulate grass and clover and plowing to expose rootstocks to frost or hot sun.
By the turn of the century, in 1905 the USDA was not mincing words:
Jumping back across the pond, a look at a 1910 English publication, “Common Weeds of the Farm and Garden,” reflects Europe’s evolving approaches. Various planting and cultivation strategies still were recommended, as were use of various tools. However, there were additional stratagems including better methods of irrigation to help crops grow stronger and more widespread, draining water from low-lying areas, use of large sheets of tarred paper to block light, and use of sand mixed with sulphate of ammonia on lawns and spraying plants with poisons such as sulphate of copper and carbolic acid. Interestingly, children were still regarded as a means of weed extirpation as it was recommended that prizes be offered to them to collect certain types of weeds.¹²
This discussion leads up to the time of discovery and use of modern herbicides which would thereafter dominate the weed science literature. While it is noted above that a manual on how to control weeds was not yet available in the early 1800’s, such publications became available around the turn of the century. The 1919 publication of the “Manual of Weeds” by Ada Georgia of Cornell University provided a definitive treatise on weeds in America and how to destroy them.¹³
The manual starts off by defining a weed as “… a plant that is growing where it is desired that something else shall grow. It follows that a plant may be a weed in some places and not in others.” The manual then discussed various mechanical and cultural approaches to weed control including this illustration of various tools used for destroying weeds.
Some of the principles of weed destruction listed included not allowing weeds to ripen to seeds, killing weeds while in the seedling stage, never plowing under weeds bearing mature seeds, using grazing animals — particularly sheep, and rotating crops. The manual then discussed the “comparatively new” way of fighting weeds, namely use of chemical herbicides, although it cautioned that further experimentation was necessary. The manual references field trials in South Dakota applying chemicals to weeds which were the first of their kind in any country. In addition to the types of chemicals mentioned in the above 1910 article from England, bichloride or mercury, kerosene, crude petroleum and arsenate of soda also were mentioned as promising chemical agents for weed extirpation.
Lastly as a new era in weed control began in the 1920’s, this article will end with a USDA publication of that time which exemplifies one of the original points made at the beginning of this article, that is, that weeds at first were, and always have been, a human construct. The following USDA Circular 89 from 1920¹⁴ extolls the virtues of a plant which thrives well in the eastern half of the United States, was regarded as an “excellent vine for arbors and porches” and “for which purpose it is commonly cultivated in most Southern cities.” It also was noted to be a useful grazing and forage crop and a cost-effective substitute for hay. This wonder plant?
Of course, years later Kudzu was being described as the “Vine that ate the South” with the reputation of the fastest and most invasive growing vine in the United States.
It so far has eluded extirpation and remains an Herba (grass) Inutilis (unprofitable, useless, worthless, disadvantageous, harmful, inutile).
By Tom Packer, North Carolina State Extension Certified Master Gardener, President of the Gardeners of Wake County, Board Member of the North Carolina Cooperative Extension Agricultural Programs Foundation, Moderator of “Gardening Carolina” Facebook Group and longtime backyard farmer in North Carolina and Northern California. Other horticulturally related articles by Mr. Packer can be found at https://medium.com/@tpacker25. All this article’s content is that of Mr. Packer alone as an individual and not as a member of or on behalf of any organizations or groups with whom he is affiliated.
___________________________________________________________________
ENDNOTES
[1] See for example North Carolina State University’s comprehensive weed control site: https://gardening.ces.ncsu.edu/weeds/
[2] Acknowledgment is given to the following sources of information from which this article quotes, summarizes, references text and ideas, and derives inspiration:
- https://wssa.net/wssa/weed/education/antique-literature/: This is a unique collection of ancient literature on weeds and weed management gathered by Dr. John D. Byrd, Jr. of Mississippi State University and maintained on the website of the Weed Science Society of America.
- Smith, Allan E. and D. M, Secoy, “Forerunners of Pesticides in Classical Greece and Rome.” J. Agric. Food Chem., Vol. 23, №6 (1975). https://www.hort.purdue.edu/newcrop/Hort_306/reading/Reading%2018-1.pdf
- Smith, Allan E., and D. M. Secoy. “Early Chemical Control of Weeds in Europe.” Weed Science 24, no. 6 (1976): 594–97. http://www.jstor.org/stable/4042614.
- Timmons, F.L., “A History of Weed Control in the United States and Canada.” Weed Science 53, November-December 2005: 748–761, originally published in Weed Science 1970, 18(2):294–307. http://www.jstor.org/stable/4046973
[3] See, endnote 2, Smith, Allan E., and D. M. Secoy. “Early Chemical Control of Weeds in Europe” at 594.
[4] https://wssa.net/wp-content/uploads/antique/Tull_Horse%20hoeing%20husbandry.pdf
[5] Blackwell, Elizabeth. 1771. “Cotula faetida (May-Weed or Faetid Camomile)
[6] https://wssa.net/wp-content/uploads/antique/communicationsvol5.pdf
[7] University of Southampton. Bill to Provide for Destruction of Weeds in Ireland. Documents. HMSO, 1860. https://jstor.org/stable/community.29942810.
[8] University of Southampton. General Abstracts of Acreage under Crops, and Live-Stock, 1875 (Appendix Regarding Extirpation of Weeds) and General Abstracts of Emigration from Irish Ports, January-July 1874 and 1875. Documents. HMSO, 1875. https://jstor.org/stable/community.29941883.
[9] Millspaugh, Charles Frederick. 1887. “Ambrosia artemisiaefolia” (Common Ragweed)
[10] McCarthy, Gerald. “American Weeds.” Science 20, no. 493 (1892): 38–38. http://www.jstor.org/stable/1768173.
[11] https://wssa.net/wp-content/uploads/WVAES_1892_Distribution-of-weeds.pdf
[13] https://wssa.net/wp-content/uploads/antique/Bailey_1919_A%20manual%20of%20weeds.pdf
[14] https://wssa.net/wp-content/uploads/kudzu89pipe.pd_.pdf
